29 Jul, 2020
1 commit
-
Some architectures may have special memory regions, within the given
memory range, which can't be used for the buffer in a kexec segment.
Implement weak arch_kexec_locate_mem_hole() definition which arch code
may override, to take care of special regions, while trying to locate
a memory hole.Also, add the missing declarations for arch overridable functions and
and drop the __weak descriptors in the declarations to avoid non-weak
definitions from becoming weak.Signed-off-by: Hari Bathini
Tested-by: Pingfan Liu
Reviewed-by: Thiago Jung Bauermann
Acked-by: Dave Young
Signed-off-by: Michael Ellerman
Link: https://lore.kernel.org/r/159602273603.575379.17665852963340380839.stgit@hbathini
16 Jun, 2020
1 commit
-
There is a regular need in the kernel to provide a way to declare having a
dynamically sized set of trailing elements in a structure. Kernel code should
always use “flexible array members”[1] for these cases. The older style of
one-element or zero-length arrays should no longer be used[2].[1] https://en.wikipedia.org/wiki/Flexible_array_member
[2] https://github.com/KSPP/linux/issues/21Signed-off-by: Gustavo A. R. Silva
28 Sep, 2019
1 commit
-
Pull kernel lockdown mode from James Morris:
"This is the latest iteration of the kernel lockdown patchset, from
Matthew Garrett, David Howells and others.From the original description:
This patchset introduces an optional kernel lockdown feature,
intended to strengthen the boundary between UID 0 and the kernel.
When enabled, various pieces of kernel functionality are restricted.
Applications that rely on low-level access to either hardware or the
kernel may cease working as a result - therefore this should not be
enabled without appropriate evaluation beforehand.The majority of mainstream distributions have been carrying variants
of this patchset for many years now, so there's value in providing a
doesn't meet every distribution requirement, but gets us much closer
to not requiring external patches.There are two major changes since this was last proposed for mainline:
- Separating lockdown from EFI secure boot. Background discussion is
covered here: https://lwn.net/Articles/751061/- Implementation as an LSM, with a default stackable lockdown LSM
module. This allows the lockdown feature to be policy-driven,
rather than encoding an implicit policy within the mechanism.The new locked_down LSM hook is provided to allow LSMs to make a
policy decision around whether kernel functionality that would allow
tampering with or examining the runtime state of the kernel should be
permitted.The included lockdown LSM provides an implementation with a simple
policy intended for general purpose use. This policy provides a coarse
level of granularity, controllable via the kernel command line:lockdown={integrity|confidentiality}
Enable the kernel lockdown feature. If set to integrity, kernel features
that allow userland to modify the running kernel are disabled. If set to
confidentiality, kernel features that allow userland to extract
confidential information from the kernel are also disabled.This may also be controlled via /sys/kernel/security/lockdown and
overriden by kernel configuration.New or existing LSMs may implement finer-grained controls of the
lockdown features. Refer to the lockdown_reason documentation in
include/linux/security.h for details.The lockdown feature has had signficant design feedback and review
across many subsystems. This code has been in linux-next for some
weeks, with a few fixes applied along the way.Stephen Rothwell noted that commit 9d1f8be5cf42 ("bpf: Restrict bpf
when kernel lockdown is in confidentiality mode") is missing a
Signed-off-by from its author. Matthew responded that he is providing
this under category (c) of the DCO"* 'next-lockdown' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/linux-security: (31 commits)
kexec: Fix file verification on S390
security: constify some arrays in lockdown LSM
lockdown: Print current->comm in restriction messages
efi: Restrict efivar_ssdt_load when the kernel is locked down
tracefs: Restrict tracefs when the kernel is locked down
debugfs: Restrict debugfs when the kernel is locked down
kexec: Allow kexec_file() with appropriate IMA policy when locked down
lockdown: Lock down perf when in confidentiality mode
bpf: Restrict bpf when kernel lockdown is in confidentiality mode
lockdown: Lock down tracing and perf kprobes when in confidentiality mode
lockdown: Lock down /proc/kcore
x86/mmiotrace: Lock down the testmmiotrace module
lockdown: Lock down module params that specify hardware parameters (eg. ioport)
lockdown: Lock down TIOCSSERIAL
lockdown: Prohibit PCMCIA CIS storage when the kernel is locked down
acpi: Disable ACPI table override if the kernel is locked down
acpi: Ignore acpi_rsdp kernel param when the kernel has been locked down
ACPI: Limit access to custom_method when the kernel is locked down
x86/msr: Restrict MSR access when the kernel is locked down
x86: Lock down IO port access when the kernel is locked down
...
26 Sep, 2019
1 commit
-
arch_kexec_kernel_image_probe function declaration has been removed by
commit 9ec4ecef0af7 ("kexec_file,x86,powerpc: factor out kexec_file_ops
functions"). Still this function is overridden by couple of architectures
and proper prototype declaration is therefore important, so bring it back.
This fixes the following sparse warning on s390:
arch/s390/kernel/machine_kexec_file.c:333:5: warning: symbol
'arch_kexec_kernel_image_probe' was not declared. Should it be static?Link: http://lkml.kernel.org/r/patch.git-ff1c9045ebdc.your-ad-here.call-01564402297-ext-5690@work.hours
Signed-off-by: Vasily Gorbik
Acked-by: Dave Young
Reviewed-by: Bhupesh Sharma
Cc: Eric Biederman
Cc: AKASHI Takahiro
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
07 Sep, 2019
2 commits
-
We're not using them, so we can drop the parsing.
Signed-off-by: Sven Schnelle
Reviewed-by: Thiago Jung Bauermann
Signed-off-by: Helge Deller -
Right now powerpc provides an implementation to read elf files
with the kexec_file_load() syscall. Make that available as a public
kexec interface so it can be re-used on other architectures.Signed-off-by: Sven Schnelle
Reviewed-by: Thiago Jung Bauermann
Signed-off-by: Helge Deller
20 Aug, 2019
1 commit
-
This is a preparatory patch for kexec_file_load() lockdown. A locked down
kernel needs to prevent unsigned kernel images from being loaded with
kexec_file_load(). Currently, the only way to force the signature
verification is compiling with KEXEC_VERIFY_SIG. This prevents loading
usigned images even when the kernel is not locked down at runtime.This patch splits KEXEC_VERIFY_SIG into KEXEC_SIG and KEXEC_SIG_FORCE.
Analogous to the MODULE_SIG and MODULE_SIG_FORCE for modules, KEXEC_SIG
turns on the signature verification but allows unsigned images to be
loaded. KEXEC_SIG_FORCE disallows images without a valid signature.Signed-off-by: Jiri Bohac
Signed-off-by: David Howells
Signed-off-by: Matthew Garrett
cc: kexec@lists.infradead.org
Signed-off-by: James Morris
27 Dec, 2018
1 commit
-
Pull x86 cleanups from Ingo Molnar:
"Misc cleanups"* 'x86-cleanups-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
x86/kprobes: Remove trampoline_handler() prototype
x86/kernel: Fix more -Wmissing-prototypes warnings
x86: Fix various typos in comments
x86/headers: Fix -Wmissing-prototypes warning
x86/process: Avoid unnecessary NULL check in get_wchan()
x86/traps: Complete prototype declarations
x86/mce: Fix -Wmissing-prototypes warnings
x86/gart: Rewrite early_gart_iommu_check() comment
06 Dec, 2018
3 commits
-
Memblock list is another source for usable system memory layout.
So move powerpc's arch_kexec_walk_mem() to common code so that other
memblock-based architectures, particularly arm64, can also utilise it.
A moved function is now renamed to kexec_walk_memblock() and integrated
into kexec_locate_mem_hole(), which will now be usable for all
architectures with no need for overriding arch_kexec_walk_mem().With this change, arch_kexec_walk_mem() need no longer be a weak function,
and was now renamed to kexec_walk_resources().Since powerpc doesn't support kdump in its kexec_file_load(), the current
kexec_walk_memblock() won't work for kdump either in this form, this will
be fixed in the next patch.Signed-off-by: AKASHI Takahiro
Cc: "Eric W. Biederman"
Acked-by: Dave Young
Cc: Vivek Goyal
Cc: Baoquan He
Acked-by: James Morse
Signed-off-by: Will Deacon -
Since s390 already knows where to locate buffers, calling
arch_kexec_mem_walk() has no sense. So we can just drop it as kbuf->mem
indicates this while all other architectures sets it to 0 initially.This change is a preparatory work for the next patch, where all the
variant memory walks, either on system resource or memblock, will be
put in one common place so that it will satisfy all the architectures'
need.Signed-off-by: AKASHI Takahiro
Reviewed-by: Philipp Rudo
Cc: Martin Schwidefsky
Cc: Heiko Carstens
Cc: Dave Young
Cc: Vivek Goyal
Cc: Baoquan He
Signed-off-by: Will Deacon -
Change this function from static to global so that arm64 can implement
its own arch_kimage_file_post_load_cleanup() later using
kexec_image_post_load_cleanup_default().Signed-off-by: AKASHI Takahiro
Acked-by: Dave Young
Cc: Vivek Goyal
Cc: Baoquan He
Signed-off-by: Will Deacon
23 Nov, 2018
1 commit
-
When building the kernel with W=1 we get a lot of -Wmissing-prototypes
warnings, which are trivial in nature and easy to fix - and which may
mask some real future bugs if the prototypes get out of sync with
the function definition.This patch fixes most of -Wmissing-prototypes warnings which
are in the root directory of arch/x86/kernel, not including
the subdirectories.These are the warnings fixed in this patch:
arch/x86/kernel/signal.c:865:17: warning: no previous prototype for ‘sys32_x32_rt_sigreturn’ [-Wmissing-prototypes]
arch/x86/kernel/signal_compat.c:164:6: warning: no previous prototype for ‘sigaction_compat_abi’ [-Wmissing-prototypes]
arch/x86/kernel/traps.c:625:46: warning: no previous prototype for ‘sync_regs’ [-Wmissing-prototypes]
arch/x86/kernel/traps.c:640:24: warning: no previous prototype for ‘fixup_bad_iret’ [-Wmissing-prototypes]
arch/x86/kernel/traps.c:929:13: warning: no previous prototype for ‘trap_init’ [-Wmissing-prototypes]
arch/x86/kernel/irq.c:270:28: warning: no previous prototype for ‘smp_x86_platform_ipi’ [-Wmissing-prototypes]
arch/x86/kernel/irq.c:301:16: warning: no previous prototype for ‘smp_kvm_posted_intr_ipi’ [-Wmissing-prototypes]
arch/x86/kernel/irq.c:314:16: warning: no previous prototype for ‘smp_kvm_posted_intr_wakeup_ipi’ [-Wmissing-prototypes]
arch/x86/kernel/irq.c:328:16: warning: no previous prototype for ‘smp_kvm_posted_intr_nested_ipi’ [-Wmissing-prototypes]
arch/x86/kernel/irq_work.c:16:28: warning: no previous prototype for ‘smp_irq_work_interrupt’ [-Wmissing-prototypes]
arch/x86/kernel/irqinit.c:79:13: warning: no previous prototype for ‘init_IRQ’ [-Wmissing-prototypes]
arch/x86/kernel/quirks.c:672:13: warning: no previous prototype for ‘early_platform_quirks’ [-Wmissing-prototypes]
arch/x86/kernel/tsc.c:1499:15: warning: no previous prototype for ‘calibrate_delay_is_known’ [-Wmissing-prototypes]
arch/x86/kernel/process.c:653:13: warning: no previous prototype for ‘arch_post_acpi_subsys_init’ [-Wmissing-prototypes]
arch/x86/kernel/process.c:717:15: warning: no previous prototype for ‘arch_randomize_brk’ [-Wmissing-prototypes]
arch/x86/kernel/process.c:784:6: warning: no previous prototype for ‘do_arch_prctl_common’ [-Wmissing-prototypes]
arch/x86/kernel/reboot.c:869:6: warning: no previous prototype for ‘nmi_panic_self_stop’ [-Wmissing-prototypes]
arch/x86/kernel/smp.c:176:27: warning: no previous prototype for ‘smp_reboot_interrupt’ [-Wmissing-prototypes]
arch/x86/kernel/smp.c:260:28: warning: no previous prototype for ‘smp_reschedule_interrupt’ [-Wmissing-prototypes]
arch/x86/kernel/smp.c:281:28: warning: no previous prototype for ‘smp_call_function_interrupt’ [-Wmissing-prototypes]
arch/x86/kernel/smp.c:291:28: warning: no previous prototype for ‘smp_call_function_single_interrupt’ [-Wmissing-prototypes]
arch/x86/kernel/ftrace.c:840:6: warning: no previous prototype for ‘arch_ftrace_update_trampoline’ [-Wmissing-prototypes]
arch/x86/kernel/ftrace.c:934:7: warning: no previous prototype for ‘arch_ftrace_trampoline_func’ [-Wmissing-prototypes]
arch/x86/kernel/ftrace.c:946:6: warning: no previous prototype for ‘arch_ftrace_trampoline_free’ [-Wmissing-prototypes]
arch/x86/kernel/crash.c:114:6: warning: no previous prototype for ‘crash_smp_send_stop’ [-Wmissing-prototypes]
arch/x86/kernel/crash.c:351:5: warning: no previous prototype for ‘crash_setup_memmap_entries’ [-Wmissing-prototypes]
arch/x86/kernel/crash.c:424:5: warning: no previous prototype for ‘crash_load_segments’ [-Wmissing-prototypes]
arch/x86/kernel/machine_kexec_64.c:372:7: warning: no previous prototype for ‘arch_kexec_kernel_image_load’ [-Wmissing-prototypes]
arch/x86/kernel/paravirt-spinlocks.c:12:16: warning: no previous prototype for ‘__native_queued_spin_unlock’ [-Wmissing-prototypes]
arch/x86/kernel/paravirt-spinlocks.c:18:6: warning: no previous prototype for ‘pv_is_native_spin_unlock’ [-Wmissing-prototypes]
arch/x86/kernel/paravirt-spinlocks.c:24:16: warning: no previous prototype for ‘__native_vcpu_is_preempted’ [-Wmissing-prototypes]
arch/x86/kernel/paravirt-spinlocks.c:30:6: warning: no previous prototype for ‘pv_is_native_vcpu_is_preempted’ [-Wmissing-prototypes]
arch/x86/kernel/kvm.c:258:1: warning: no previous prototype for ‘do_async_page_fault’ [-Wmissing-prototypes]
arch/x86/kernel/jailhouse.c:200:6: warning: no previous prototype for ‘jailhouse_paravirt’ [-Wmissing-prototypes]
arch/x86/kernel/check.c:91:13: warning: no previous prototype for ‘setup_bios_corruption_check’ [-Wmissing-prototypes]
arch/x86/kernel/check.c:139:6: warning: no previous prototype for ‘check_for_bios_corruption’ [-Wmissing-prototypes]
arch/x86/kernel/devicetree.c:32:13: warning: no previous prototype for ‘early_init_dt_scan_chosen_arch’ [-Wmissing-prototypes]
arch/x86/kernel/devicetree.c:42:13: warning: no previous prototype for ‘add_dtb’ [-Wmissing-prototypes]
arch/x86/kernel/devicetree.c:108:6: warning: no previous prototype for ‘x86_of_pci_init’ [-Wmissing-prototypes]
arch/x86/kernel/devicetree.c:314:13: warning: no previous prototype for ‘x86_dtb_init’ [-Wmissing-prototypes]
arch/x86/kernel/tracepoint.c:16:5: warning: no previous prototype for ‘trace_pagefault_reg’ [-Wmissing-prototypes]
arch/x86/kernel/tracepoint.c:22:6: warning: no previous prototype for ‘trace_pagefault_unreg’ [-Wmissing-prototypes]
arch/x86/kernel/head64.c:113:22: warning: no previous prototype for ‘__startup_64’ [-Wmissing-prototypes]
arch/x86/kernel/head64.c:262:15: warning: no previous prototype for ‘__startup_secondary_64’ [-Wmissing-prototypes]
arch/x86/kernel/head64.c:350:12: warning: no previous prototype for ‘early_make_pgtable’ [-Wmissing-prototypes][ mingo: rewrote the changelog, fixed build errors. ]
Signed-off-by: Yi Wang
Cc: Linus Torvalds
Cc: Peter Zijlstra
Cc: Thomas Gleixner
Cc: akataria@vmware.com
Cc: akpm@linux-foundation.org
Cc: andy.shevchenko@gmail.com
Cc: anton@enomsg.org
Cc: ard.biesheuvel@linaro.org
Cc: bhe@redhat.com
Cc: bhelgaas@google.com
Cc: bp@alien8.de
Cc: ccross@android.com
Cc: devicetree@vger.kernel.org
Cc: douly.fnst@cn.fujitsu.com
Cc: dwmw@amazon.co.uk
Cc: dyoung@redhat.com
Cc: ebiederm@xmission.com
Cc: frank.rowand@sony.com
Cc: frowand.list@gmail.com
Cc: ivan.gorinov@intel.com
Cc: jailhouse-dev@googlegroups.com
Cc: jan.kiszka@siemens.com
Cc: jgross@suse.com
Cc: jroedel@suse.de
Cc: keescook@chromium.org
Cc: kexec@lists.infradead.org
Cc: konrad.wilk@oracle.com
Cc: kvm@vger.kernel.org
Cc: linux-efi@vger.kernel.org
Cc: linux-pci@vger.kernel.org
Cc: luto@kernel.org
Cc: m.mizuma@jp.fujitsu.com
Cc: namit@vmware.com
Cc: oleg@redhat.com
Cc: pasha.tatashin@oracle.com
Cc: pbonzini@redhat.com
Cc: prarit@redhat.com
Cc: pravin.shedge4linux@gmail.com
Cc: rajvi.jingar@intel.com
Cc: rkrcmar@redhat.com
Cc: robh+dt@kernel.org
Cc: robh@kernel.org
Cc: rostedt@goodmis.org
Cc: takahiro.akashi@linaro.org
Cc: thomas.lendacky@amd.com
Cc: tony.luck@intel.com
Cc: up2wing@gmail.com
Cc: virtualization@lists.linux-foundation.org
Cc: zhe.he@windriver.com
Cc: zhong.weidong@zte.com.cn
Link: http://lkml.kernel.org/r/1542852249-19820-1-git-send-email-wang.yi59@zte.com.cn
Signed-off-by: Ingo Molnar
14 Apr, 2018
6 commits
-
For s390 new kernels are loaded to fixed addresses in memory before they
are booted. With the current code this is a problem as it assumes the
kernel will be loaded to an 'arbitrary' address. In particular,
kexec_locate_mem_hole searches for a large enough memory region and sets
the load address (kexec_bufer->mem) to it.Luckily there is a simple workaround for this problem. By returning 1
in arch_kexec_walk_mem, kexec_locate_mem_hole is turned off. This
allows the architecture to set kbuf->mem by hand. While the trick works
fine for the kernel it does not for the purgatory as here the
architectures don't have access to its kexec_buffer.Give architectures access to the purgatories kexec_buffer by changing
kexec_load_purgatory to take a pointer to it. With this change
architectures have access to the buffer and can edit it as they need.A nice side effect of this change is that we can get rid of the
purgatory_info->purgatory_load_address field. As now the information
stored there can directly be accessed from kbuf->mem.Link: http://lkml.kernel.org/r/20180321112751.22196-11-prudo@linux.vnet.ibm.com
Signed-off-by: Philipp Rudo
Reviewed-by: Martin Schwidefsky
Acked-by: Dave Young
Cc: AKASHI Takahiro
Cc: Eric Biederman
Cc: Heiko Carstens
Cc: Ingo Molnar
Cc: Michael Ellerman
Cc: Thiago Jung Bauermann
Cc: Vivek Goyal
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
When the relocations are applied to the purgatory only the section the
relocations are applied to is writable. The other sections, i.e. the
symtab and .rel/.rela, are in read-only kexec_purgatory. Highlight this
by marking the corresponding variables as 'const'.While at it also change the signatures of arch_kexec_apply_relocations* to
take section pointers instead of just the index of the relocation section.
This removes the second lookup and sanity check of the sections in arch
code.Link: http://lkml.kernel.org/r/20180321112751.22196-6-prudo@linux.vnet.ibm.com
Signed-off-by: Philipp Rudo
Acked-by: Dave Young
Cc: AKASHI Takahiro
Cc: Eric Biederman
Cc: Heiko Carstens
Cc: Ingo Molnar
Cc: Martin Schwidefsky
Cc: Michael Ellerman
Cc: Thiago Jung Bauermann
Cc: Vivek Goyal
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
The kexec_purgatory buffer is read-only. Thus all pointers into
kexec_purgatory are read-only, too. Point this out by explicitly
marking purgatory_info->ehdr as 'const' and update the comments in
purgatory_info.Link: http://lkml.kernel.org/r/20180321112751.22196-4-prudo@linux.vnet.ibm.com
Signed-off-by: Philipp Rudo
Acked-by: Dave Young
Cc: AKASHI Takahiro
Cc: Eric Biederman
Cc: Heiko Carstens
Cc: Ingo Molnar
Cc: Martin Schwidefsky
Cc: Michael Ellerman
Cc: Thiago Jung Bauermann
Cc: Vivek Goyal
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
Patch series "kexec_file: Clean up purgatory load", v2.
Following the discussion with Dave and AKASHI, here are the common code
patches extracted from my recent patch set (Add kexec_file_load support
to s390) [1]. The patches were extracted to allow upstream integration
together with AKASHI's common code patches before the arch code gets
adjusted to the new base.The reason for this series is to prepare common code for adding
kexec_file_load to s390 as well as cleaning up the mis-use of the
sh_offset field during purgatory load. In detail this series contains:Patch #1&2: Minor cleanups/fixes.
Patch #3-9: Clean up the purgatory load/relocation code. Especially
remove the mis-use of the purgatory_info->sechdrs->sh_offset field,
currently holding a pointer into either kexec_purgatory (ro) or
purgatory_buf (rw) depending on the section. With these patches the
section address will be calculated verbosely and sh_offset will contain
the offset of the section in the stripped purgatory binary
(purgatory_buf).Patch #10: Allows architectures to set the purgatory load address. This
patch is important for s390 as the kernel and purgatory have to be
loaded to fixed addresses. In current code this is impossible as the
purgatory load is opaque to the architecture.Patch #11: Moves x86 purgatories sha implementation to common lib/
directory to allow reuse in other architectures.This patch (of 11)
When building the kernel with CONFIG_KEXEC_FILE enabled gcc prints a
compile warning multiple times.In file included from /linux/init/initramfs.c:526:0:
/include/linux/kexec.h:120:9: warning: `struct kimage' declared inside parameter list [enabled by default]
unsigned long cmdline_len);
^This is because the typedefs for kexec_file_load uses struct kimage
before it is declared. Fix this by simply forward declaring struct
kimage.Link: http://lkml.kernel.org/r/20180321112751.22196-2-prudo@linux.vnet.ibm.com
Signed-off-by: Philipp Rudo
Acked-by: Dave Young
Cc: Eric Biederman
Cc: Vivek Goyal
Cc: Michael Ellerman
Cc: Thiago Jung Bauermann
Cc: Martin Schwidefsky
Cc: Heiko Carstens
Cc: AKASHI Takahiro
Cc: Ingo Molnar
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
In the previous patches, commonly-used routines, exclude_mem_range() and
prepare_elf64_headers(), were carved out. Now place them in kexec
common code. A prefix "crash_" is given to each of their names to avoid
possible name collisions.Link: http://lkml.kernel.org/r/20180306102303.9063-8-takahiro.akashi@linaro.org
Signed-off-by: AKASHI Takahiro
Acked-by: Dave Young
Tested-by: Dave Young
Cc: Vivek Goyal
Cc: Baoquan He
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
As arch_kexec_kernel_image_{probe,load}(),
arch_kimage_file_post_load_cleanup() and arch_kexec_kernel_verify_sig()
are almost duplicated among architectures, they can be commonalized with
an architecture-defined kexec_file_ops array. So let's factor them out.Link: http://lkml.kernel.org/r/20180306102303.9063-3-takahiro.akashi@linaro.org
Signed-off-by: AKASHI Takahiro
Acked-by: Dave Young
Tested-by: Dave Young
Cc: Vivek Goyal
Cc: Baoquan He
Cc: Michael Ellerman
Cc: Thiago Jung Bauermann
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
03 Apr, 2018
1 commit
-
As the syscall function should only be called from the system call table
but not from elsewhere in the kernel, move the prototype for
sys_kexec_load() to include/syscall.h.Cc: Eric Biederman
Cc: kexec@lists.infradead.org
Signed-off-by: Dominik Brodowski
07 Nov, 2017
1 commit
-
In preperation for a new function that will need additional resource
information during the resource walk, update the resource walk callback to
pass the resource structure. Since the current callback start and end
arguments are pulled from the resource structure, the callback functions
can obtain them from the resource structure directly.Signed-off-by: Tom Lendacky
Signed-off-by: Brijesh Singh
Signed-off-by: Thomas Gleixner
Reviewed-by: Kees Cook
Reviewed-by: Borislav Petkov
Tested-by: Borislav Petkov
Cc: kvm@vger.kernel.org
Cc: Benjamin Herrenschmidt
Cc: Borislav Petkov
Cc: linuxppc-dev@lists.ozlabs.org
Link: https://lkml.kernel.org/r/20171020143059.3291-10-brijesh.singh@amd.com
02 Nov, 2017
1 commit
-
Many source files in the tree are missing licensing information, which
makes it harder for compliance tools to determine the correct license.By default all files without license information are under the default
license of the kernel, which is GPL version 2.Update the files which contain no license information with the 'GPL-2.0'
SPDX license identifier. The SPDX identifier is a legally binding
shorthand, which can be used instead of the full boiler plate text.This patch is based on work done by Thomas Gleixner and Kate Stewart and
Philippe Ombredanne.How this work was done:
Patches were generated and checked against linux-4.14-rc6 for a subset of
the use cases:
- file had no licensing information it it.
- file was a */uapi/* one with no licensing information in it,
- file was a */uapi/* one with existing licensing information,Further patches will be generated in subsequent months to fix up cases
where non-standard license headers were used, and references to license
had to be inferred by heuristics based on keywords.The analysis to determine which SPDX License Identifier to be applied to
a file was done in a spreadsheet of side by side results from of the
output of two independent scanners (ScanCode & Windriver) producing SPDX
tag:value files created by Philippe Ombredanne. Philippe prepared the
base worksheet, and did an initial spot review of a few 1000 files.The 4.13 kernel was the starting point of the analysis with 60,537 files
assessed. Kate Stewart did a file by file comparison of the scanner
results in the spreadsheet to determine which SPDX license identifier(s)
to be applied to the file. She confirmed any determination that was not
immediately clear with lawyers working with the Linux Foundation.Criteria used to select files for SPDX license identifier tagging was:
- Files considered eligible had to be source code files.
- Make and config files were included as candidates if they contained >5
lines of source
- File already had some variant of a license header in it (even if
Reviewed-by: Philippe Ombredanne
Reviewed-by: Thomas Gleixner
Signed-off-by: Greg Kroah-Hartman
18 Jul, 2017
1 commit
-
Provide support so that kexec can be used to boot a kernel when SME is
enabled.Support is needed to allocate pages for kexec without encryption. This
is needed in order to be able to reboot in the kernel in the same manner
as originally booted.Additionally, when shutting down all of the CPUs we need to be sure to
flush the caches and then halt. This is needed when booting from a state
where SME was not active into a state where SME is active (or vice-versa).
Without these steps, it is possible for cache lines to exist for the same
physical location but tagged both with and without the encryption bit. This
can cause random memory corruption when caches are flushed depending on
which cacheline is written last.Signed-off-by: Tom Lendacky
Reviewed-by: Thomas Gleixner
Reviewed-by: Borislav Petkov
Cc:
Cc: Alexander Potapenko
Cc: Andrey Ryabinin
Cc: Andy Lutomirski
Cc: Arnd Bergmann
Cc: Borislav Petkov
Cc: Brijesh Singh
Cc: Dave Young
Cc: Dmitry Vyukov
Cc: Jonathan Corbet
Cc: Konrad Rzeszutek Wilk
Cc: Larry Woodman
Cc: Linus Torvalds
Cc: Matt Fleming
Cc: Michael S. Tsirkin
Cc: Paolo Bonzini
Cc: Peter Zijlstra
Cc: Radim Krčmář
Cc: Rik van Riel
Cc: Toshimitsu Kani
Cc: kasan-dev@googlegroups.com
Cc: kvm@vger.kernel.org
Cc: linux-arch@vger.kernel.org
Cc: linux-doc@vger.kernel.org
Cc: linux-efi@vger.kernel.org
Cc: linux-mm@kvack.org
Link: http://lkml.kernel.org/r/b95ff075db3e7cd545313f2fb609a49619a09625.1500319216.git.thomas.lendacky@amd.com
Signed-off-by: Ingo Molnar
13 Jul, 2017
1 commit
-
Currently vmcoreinfo data is updated at boot time subsys_initcall(), it
has the risk of being modified by some wrong code during system is
running.As a result, vmcore dumped may contain the wrong vmcoreinfo. Later on,
when using "crash", "makedumpfile", etc utility to parse this vmcore, we
probably will get "Segmentation fault" or other unexpected errors.E.g. 1) wrong code overwrites vmcoreinfo_data; 2) further crashes the
system; 3) trigger kdump, then we obviously will fail to recognize the
crash context correctly due to the corrupted vmcoreinfo.Now except for vmcoreinfo, all the crash data is well
protected(including the cpu note which is fully updated in the crash
path, thus its correctness is guaranteed). Given that vmcoreinfo data
is a large chunk prepared for kdump, we better protect it as well.To solve this, we relocate and copy vmcoreinfo_data to the crash memory
when kdump is loading via kexec syscalls. Because the whole crash
memory will be protected by existing arch_kexec_protect_crashkres()
mechanism, we naturally protect vmcoreinfo_data from write(even read)
access under kernel direct mapping after kdump is loaded.Since kdump is usually loaded at the very early stage after boot, we can
trust the correctness of the vmcoreinfo data copied.On the other hand, we still need to operate the vmcoreinfo safe copy
when crash happens to generate vmcoreinfo_note again, we rely on vmap()
to map out a new kernel virtual address and update to use this new one
instead in the following crash_save_vmcoreinfo().BTW, we do not touch vmcoreinfo_note, because it will be fully updated
using the protected vmcoreinfo_data after crash which is surely correct
just like the cpu crash note.Link: http://lkml.kernel.org/r/1493281021-20737-3-git-send-email-xlpang@redhat.com
Signed-off-by: Xunlei Pang
Tested-by: Michael Holzheu
Cc: Benjamin Herrenschmidt
Cc: Dave Young
Cc: Eric Biederman
Cc: Hari Bathini
Cc: Juergen Gross
Cc: Mahesh Salgaonkar
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
05 Jul, 2017
1 commit
-
After commmit 692f66f26a4c19 ("crash: move crashkernel parsing and vmcore
related code under CONFIG_CRASH_CORE") the KEXEC_NOTE_BYTES macro is not
used anymore and for s390 we create the ELF header in the new kernel
anyway. Therefore remove the macro.Reported-by: Xunlei Pang
Reviewed-by: Mikhail Zaslonko
Signed-off-by: Michael Holzheu
Signed-off-by: Martin Schwidefsky
09 May, 2017
1 commit
-
Patch series "kexec/fadump: remove dependency with CONFIG_KEXEC and
reuse crashkernel parameter for fadump", v4.Traditionally, kdump is used to save vmcore in case of a crash. Some
architectures like powerpc can save vmcore using architecture specific
support instead of kexec/kdump mechanism. Such architecture specific
support also needs to reserve memory, to be used by dump capture kernel.
crashkernel parameter can be a reused, for memory reservation, by such
architecture specific infrastructure.This patchset removes dependency with CONFIG_KEXEC for crashkernel
parameter and vmcoreinfo related code as it can be reused without kexec
support. Also, crashkernel parameter is reused instead of
fadump_reserve_mem to reserve memory for fadump.The first patch moves crashkernel parameter parsing and vmcoreinfo
related code under CONFIG_CRASH_CORE instead of CONFIG_KEXEC_CORE. The
second patch reuses the definitions of append_elf_note() & final_note()
functions under CONFIG_CRASH_CORE in IA64 arch code. The third patch
removes dependency on CONFIG_KEXEC for firmware-assisted dump (fadump)
in powerpc. The next patch reuses crashkernel parameter for reserving
memory for fadump, instead of the fadump_reserve_mem parameter. This
has the advantage of using all syntaxes crashkernel parameter supports,
for fadump as well. The last patch updates fadump kernel documentation
about use of crashkernel parameter.This patch (of 5):
Traditionally, kdump is used to save vmcore in case of a crash. Some
architectures like powerpc can save vmcore using architecture specific
support instead of kexec/kdump mechanism. Such architecture specific
support also needs to reserve memory, to be used by dump capture kernel.
crashkernel parameter can be a reused, for memory reservation, by such
architecture specific infrastructure.But currently, code related to vmcoreinfo and parsing of crashkernel
parameter is built under CONFIG_KEXEC_CORE. This patch introduces
CONFIG_CRASH_CORE and moves the above mentioned code under this config,
allowing code reuse without dependency on CONFIG_KEXEC. There is no
functional change with this patch.Link: http://lkml.kernel.org/r/149035338104.6881.4550894432615189948.stgit@hbathini.in.ibm.com
Signed-off-by: Hari Bathini
Acked-by: Dave Young
Cc: Fenghua Yu
Cc: Tony Luck
Cc: Eric Biederman
Cc: Mahesh Salgaonkar
Cc: Vivek Goyal
Cc: Michael Ellerman
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
17 Dec, 2016
1 commit
-
Pull powerpc updates from Michael Ellerman:
"Highlights include:- Support for the kexec_file_load() syscall, which is a prereq for
secure and trusted boot.- Prevent kernel execution of userspace on P9 Radix (similar to
SMEP/PXN).- Sort the exception tables at build time, to save time at boot, and
store them as relative offsets to save space in the kernel image &
memory.- Allow building the kernel with thin archives, which should allow us
to build an allyesconfig once some other fixes land.- Build fixes to allow us to correctly rebuild when changing the
kernel endian from big to little or vice versa.- Plumbing so that we can avoid doing a full mm TLB flush on P9
Radix.- Initial stack protector support (-fstack-protector).
- Support for dumping the radix (aka. Linux) and hash page tables via
debugfs.- Fix an oops in cxl coredump generation when cxl_get_fd() is used.
- Freescale updates from Scott: "Highlights include 8xx hugepage
support, qbman fixes/cleanup, device tree updates, and some misc
cleanup."- Many and varied fixes and minor enhancements as always.
Thanks to:
Alexey Kardashevskiy, Andrew Donnellan, Aneesh Kumar K.V, Anshuman
Khandual, Anton Blanchard, Balbir Singh, Bartlomiej Zolnierkiewicz,
Christophe Jaillet, Christophe Leroy, Denis Kirjanov, Elimar
Riesebieter, Frederic Barrat, Gautham R. Shenoy, Geliang Tang, Geoff
Levand, Jack Miller, Johan Hovold, Lars-Peter Clausen, Libin,
Madhavan Srinivasan, Michael Neuling, Nathan Fontenot, Naveen N.
Rao, Nicholas Piggin, Pan Xinhui, Peter Senna Tschudin, Rashmica
Gupta, Rui Teng, Russell Currey, Scott Wood, Simon Guo, Suraj
Jitindar Singh, Thiago Jung Bauermann, Tobias Klauser, Vaibhav Jain"[ And thanks to Michael, who took time off from a new baby to get this
pull request done. - Linus ]* tag 'powerpc-4.10-1' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux: (174 commits)
powerpc/fsl/dts: add FMan node for t1042d4rdb
powerpc/fsl/dts: add sg_2500_aqr105_phy4 alias on t1024rdb
powerpc/fsl/dts: add QMan and BMan nodes on t1024
powerpc/fsl/dts: add QMan and BMan nodes on t1023
soc/fsl/qman: test: use DEFINE_SPINLOCK()
powerpc/fsl-lbc: use DEFINE_SPINLOCK()
powerpc/8xx: Implement support of hugepages
powerpc: get hugetlbpage handling more generic
powerpc: port 64 bits pgtable_cache to 32 bits
powerpc/boot: Request no dynamic linker for boot wrapper
soc/fsl/bman: Use resource_size instead of computation
soc/fsl/qe: use builtin_platform_driver
powerpc/fsl_pmc: use builtin_platform_driver
powerpc/83xx/suspend: use builtin_platform_driver
powerpc/ftrace: Fix the comments for ftrace_modify_code
powerpc/perf: macros for power9 format encoding
powerpc/perf: power9 raw event format encoding
powerpc/perf: update attribute_group data structure
powerpc/perf: factor out the event format field
powerpc/mm/iommu, vfio/spapr: Put pages on VFIO container shutdown
...
15 Dec, 2016
1 commit
-
This reverts commit 0549a3c02efb ("kdump, vmcoreinfo: report memory
sections virtual addresses").Commit 0549a3c02efb tells the userspace utility makedumpfile the
randomized base address of these memmory sections when mm kaslr is
enabled. However the following patch "kexec: export the value of
phys_base instead of symbol address" makes makedumpfile not need these
addresses any more.Besides we should use VMCOREINFO_NUMBER to export the value of the
variable so that we can use the existing number_table mechanism of
Makedumpfile to fetch it. So revert it now. If needed we can add it
later.http://lists.infradead.org/pipermail/kexec/2016-October/017540.html
Link: http://lkml.kernel.org/r/1478568596-30060-1-git-send-email-bhe@redhat.com
Signed-off-by: Baoquan He
Cc: Thomas Garnier
Cc: Baoquan He
Cc: Thomas Gleixner
Cc: Ingo Molnar
Cc: "H . Peter Anvin"
Cc: Eric Biederman
Cc: Xunlei Pang
Cc: HATAYAMA Daisuke
Cc: Kees Cook
Cc: Eugene Surovegin
Cc: Dave Young
Cc: AKASHI Takahiro
Cc: Atsushi Kumagai
Cc: Dave Anderson
Cc: Pratyush Anand
Cc: Vivek Goyal
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
30 Nov, 2016
3 commits
-
kexec_locate_mem_hole will be used by the PowerPC kexec_file_load
implementation to find free memory for the purgatory stack.Signed-off-by: Thiago Jung Bauermann
Acked-by: Dave Young
Signed-off-by: Michael Ellerman -
This is done to simplify the kexec_add_buffer argument list.
Adapt all callers to set up a kexec_buf to pass to kexec_add_buffer.In addition, change the type of kexec_buf.buffer from char * to void *.
There is no particular reason for it to be a char *, and the change
allows us to get rid of 3 existing casts to char * in the code.Signed-off-by: Thiago Jung Bauermann
Acked-by: Dave Young
Acked-by: Balbir Singh
Signed-off-by: Michael Ellerman -
Allow architectures to specify a different memory walking function for
kexec_add_buffer. x86 uses iomem to track reserved memory ranges, but
PowerPC uses the memblock subsystem.Signed-off-by: Thiago Jung Bauermann
Acked-by: Dave Young
Acked-by: Balbir Singh
Signed-off-by: Michael Ellerman
12 Oct, 2016
1 commit
-
KASLR memory randomization can randomize the base of the physical memory
mapping (PAGE_OFFSET), vmalloc (VMALLOC_START) and vmemmap
(VMEMMAP_START). Adding these variables on VMCOREINFO so tools can easily
identify the base of each memory section.Link: http://lkml.kernel.org/r/1471531632-23003-1-git-send-email-thgarnie@google.com
Signed-off-by: Thomas Garnier
Acked-by: Baoquan He
Cc: Thomas Gleixner
Cc: Ingo Molnar
Cc: "H . Peter Anvin"
Cc: Eric Biederman
Cc: Xunlei Pang
Cc: HATAYAMA Daisuke
Cc: Kees Cook
Cc: Eugene Surovegin
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
03 Aug, 2016
4 commits
-
Provide a wrapper function to be used by kernel code to check whether a
crash kernel is loaded. It returns the same value that can be seen in
/sys/kernel/kexec_crash_loaded by userspace programs.I'm exporting the function, because it will be used by Xen, and it is
possible to compile Xen modules separately to enable the use of PV
drivers with unmodified bare-metal kernels.Link: http://lkml.kernel.org/r/20160713121955.14969.69080.stgit@hananiah.suse.cz
Signed-off-by: Petr Tesarik
Cc: Juergen Gross
Cc: Josh Triplett
Cc: Ingo Molnar
Cc: Thomas Gleixner
Cc: Eric Biederman
Cc: "H. Peter Anvin"
Cc: Boris Ostrovsky
Cc: "Paul E. McKenney"
Cc: Dave Young
Cc: David Vrabel
Cc: Vivek Goyal
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
kexec physical addresses are the boot-time view of the system. For
certain ARM systems (such as Keystone 2), the boot view of the system
does not match the kernel's view of the system: the boot view uses a
special alias in the lower 4GB of the physical address space.To cater for these kinds of setups, we need to translate between the
boot view physical addresses and the normal kernel view physical
addresses. This patch extracts the current transation points into
linux/kexec.h, and allows an architecture to override the functions.Due to the translations required, we unfortunately end up with six
translation functions, which are reduced down to four that the
architecture can override.[akpm@linux-foundation.org: kexec.h needs asm/io.h for phys_to_virt()]
Link: http://lkml.kernel.org/r/E1b8koP-0004HZ-Vf@rmk-PC.armlinux.org.uk
Signed-off-by: Russell King
Cc: Keerthy
Cc: Pratyush Anand
Cc: Vitaly Andrianov
Cc: Eric Biederman
Cc: Dave Young
Cc: Baoquan He
Cc: Vivek Goyal
Cc: Simon Horman
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
On PAE systems (eg, ARM LPAE) the vmcore note may be located above 4GB
physical on 32-bit architectures, so we need a wider type than "unsigned
long" here. Arrange for paddr_vmcoreinfo_note() to return a
phys_addr_t, thereby allowing it to be located above 4GB.This makes no difference for kexec-tools, as they already assume a
64-bit type when reading from this file.Link: http://lkml.kernel.org/r/E1b8koK-0004HS-K9@rmk-PC.armlinux.org.uk
Signed-off-by: Russell King
Reviewed-by: Pratyush Anand
Acked-by: Baoquan He
Cc: Keerthy
Cc: Vitaly Andrianov
Cc: Eric Biederman
Cc: Dave Young
Cc: Vivek Goyal
Cc: Simon Horman
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
If we are unable to find a suitable page when allocating the control
page, do not invoke the OOM-killer: killing processes probably isn't
going to help.Link: http://lkml.kernel.org/r/E1b8ko9-0004HG-R5@rmk-PC.armlinux.org.uk
Signed-off-by: Russell King
Reviewed-by: Pratyush Anand
Acked-by: Baoquan He
Cc: Keerthy
Cc: Vitaly Andrianov
Cc: Eric Biederman
Cc: Dave Young
Cc: Vivek Goyal
Cc: Simon Horman
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
24 May, 2016
2 commits
-
…unprotect)_crashkres()
Commit 3f625002581b ("kexec: introduce a protection mechanism for the
crashkernel reserved memory") is a similar mechanism for protecting the
crash kernel reserved memory to previous crash_map/unmap_reserved_pages()
implementation, the new one is more generic in name and cleaner in code
(besides, some arch may not be allowed to unmap the pgtable).Therefore, this patch consolidates them, and uses the new
arch_kexec_protect(unprotect)_crashkres() to replace former
crash_map/unmap_reserved_pages() which by now has been only used by
S390.The consolidation work needs the crash memory to be mapped initially,
this is done in machine_kdump_pm_init() which is after
reserve_crashkernel(). Once kdump kernel is loaded, the new
arch_kexec_protect_crashkres() implemented for S390 will actually
unmap the pgtable like before.Signed-off-by: Xunlei Pang <xlpang@redhat.com>
Signed-off-by: Michael Holzheu <holzheu@linux.vnet.ibm.com>
Acked-by: Michael Holzheu <holzheu@linux.vnet.ibm.com>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: Minfei Huang <mhuang@redhat.com>
Cc: Vivek Goyal <vgoyal@redhat.com>
Cc: Dave Young <dyoung@redhat.com>
Cc: Baoquan He <bhe@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> -
For the cases that some kernel (module) path stamps the crash reserved
memory(already mapped by the kernel) where has been loaded the second
kernel data, the kdump kernel will probably fail to boot when panic
happens (or even not happens) leaving the culprit at large, this is
unacceptable.The patch introduces a mechanism for detecting such cases:
1) After each crash kexec loading, it simply marks the reserved memory
regions readonly since we no longer access it after that. When someone
stamps the region, the first kernel will panic and trigger the kdump.
The weak arch_kexec_protect_crashkres() is introduced to do the actual
protection.2) To allow multiple loading, once 1) was done we also need to remark
the reserved memory to readwrite each time a system call related to
kdump is made. The weak arch_kexec_unprotect_crashkres() is introduced
to do the actual protection.The architecture can make its specific implementation by overriding
arch_kexec_protect_crashkres() and arch_kexec_unprotect_crashkres().Signed-off-by: Xunlei Pang
Cc: Eric Biederman
Cc: Dave Young
Cc: Minfei Huang
Cc: Vivek Goyal
Cc: Baoquan He
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
21 Jan, 2016
1 commit
-
Move the stuff currently only used by the kexec file code within
CONFIG_KEXEC_FILE (and CONFIG_KEXEC_VERIFY_SIG).Also move internal "struct kexec_sha_region" and "struct kexec_buf" into
"kexec_internal.h".Signed-off-by: Xunlei Pang
Cc: "Eric W. Biederman"
Cc: Dave Young
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
19 Dec, 2015
1 commit
-
Currently, panic() and crash_kexec() can be called at the same time.
For example (x86 case):CPU 0:
oops_end()
crash_kexec()
mutex_trylock() // acquired
nmi_shootdown_cpus() // stop other CPUsCPU 1:
panic()
crash_kexec()
mutex_trylock() // failed to acquire
smp_send_stop() // stop other CPUs
infinite loopIf CPU 1 calls smp_send_stop() before nmi_shootdown_cpus(), kdump
fails.In another case:
CPU 0:
oops_end()
crash_kexec()
mutex_trylock() // acquired
io_check_error()
panic()
crash_kexec()
mutex_trylock() // failed to acquire
infinite loopClearly, this is an undesirable result.
To fix this problem, this patch changes crash_kexec() to exclude others
by using the panic_cpu atomic.Signed-off-by: Hidehiro Kawai
Acked-by: Michal Hocko
Cc: Andrew Morton
Cc: Baoquan He
Cc: Dave Young
Cc: "Eric W. Biederman"
Cc: HATAYAMA Daisuke
Cc: "H. Peter Anvin"
Cc: Ingo Molnar
Cc: Jonathan Corbet
Cc: kexec@lists.infradead.org
Cc: linux-doc@vger.kernel.org
Cc: Martin Schwidefsky
Cc: Masami Hiramatsu
Cc: Minfei Huang
Cc: Peter Zijlstra
Cc: Seth Jennings
Cc: Steven Rostedt
Cc: Thomas Gleixner
Cc: Vitaly Kuznetsov
Cc: Vivek Goyal
Cc: x86-ml
Link: http://lkml.kernel.org/r/20151210014630.25437.94161.stgit@softrs
Signed-off-by: Borislav Petkov
Signed-off-by: Thomas Gleixner
11 Sep, 2015
1 commit
-
There are two kexec load syscalls, kexec_load another and kexec_file_load.
kexec_file_load has been splited as kernel/kexec_file.c. In this patch I
split kexec_load syscall code to kernel/kexec.c.And add a new kconfig option KEXEC_CORE, so we can disable kexec_load and
use kexec_file_load only, or vice verse.The original requirement is from Ted Ts'o, he want kexec kernel signature
being checked with CONFIG_KEXEC_VERIFY_SIG enabled. But kexec-tools use
kexec_load syscall can bypass the checking.Vivek Goyal proposed to create a common kconfig option so user can compile
in only one syscall for loading kexec kernel. KEXEC/KEXEC_FILE selects
KEXEC_CORE so that old config files still work.Because there's general code need CONFIG_KEXEC_CORE, so I updated all the
architecture Kconfig with a new option KEXEC_CORE, and let KEXEC selects
KEXEC_CORE in arch Kconfig. Also updated general kernel code with to
kexec_load syscall.[akpm@linux-foundation.org: coding-style fixes]
Signed-off-by: Dave Young
Cc: Eric W. Biederman
Cc: Vivek Goyal
Cc: Petr Tesarik
Cc: Theodore Ts'o
Cc: Josh Boyer
Cc: David Howells
Cc: Geert Uytterhoeven
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
